On: The games Nintendo didn't want you to play: Tengen

[ndiddy]

The "voltage spike" method caused a cat-and-mouse game between Nintendo and the unlicensed game companies, where Nintendo would make a new NES board revision and then the companies had to figure out a way around their new current protection. Some companies even published directions in their game manuals for how to modify the NES console to get around the protection: https://files.catbox.moe/9t03p6.png

[TedDoesntTalk → ndiddy]

> Nintendo would make a new NES board revision and then the companies had to figure out

I don’t understand how they can Do that and still maintain backwards compatibility with old cartridges?

[toast0 → TedDoesntTalk]

The changes only broke (some) unlicensed cartridges, it didn't break cartridges that had a Nintendo manufactured protection chip.

[tedunangst → TedDoesntTalk]

You stick a diode on the reverse fry line, so sending -5v resets the console instead of the copy chip.